40Ar/39Ar geochronologic data for a basaltic tuff exposed in a paleoseismic trench across the Anvil Lake fault, Clackamas River fault zone, Oregon

40Ar/39Ar geochronologic data presented in this data release are for a basaltic tuff exposed in a paleoseismic trench across the Anvil Lake fault, Clackamas River fault zone, Oregon. These data were collected to determine the age of volcanic bedrock in the footwall of the Anvil Lake fault, exposed during the paleoseismic trench study. These data provide constraints for the slip rate of the Anvil Lake fault and for the onset of fault activity across the greater Clackamas River fault zone. These data will help in updating the geologic map in this part of the northern Oregon Cascade Range, located west of Timothy Lake and north of Oak Grove Fork Clackamas River.